JPH04293448A - Agent for keeping freshness of green vegetable and flower and its use - Google Patents

Abstract

PURPOSE:To provide an agent for keeping the freshness of green vegetables and flowers and provide a method for the use of the agent. CONSTITUTION:The objective freshness-keeping agent can be produced by mixing (A) a solution of a palladium complex salt and (B) a solution of a salt and/or a complex salt of at least one kind of metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver and platinum and heat-treating the produced precipitate. The agent is used in the form dispersed in a molded article. The obtained freshness-keeping agent is effective for decomposing and eliminating the physiologically active substances generated from green vegetables and flowers and has high safety. The freshness of green vegetables and flowers can be maintained by placing the agent together with the green vegetables and flowers or by using the molded article containing the agent in dispersed state as the packaging material or storage vessel for the green vegetables and flowers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a freshness-preserving agent for fruits, vegetables, and flowers, and a method for using the same. More specifically, it is a freshness-preserving agent that effectively maintains the freshness of fruits, vegetables, and flowers by decomposing and removing physiologically active substances such as ethylene and acetaldehyde generated from the fruits and flowers into substances that are harmless to the fruits, vegetables, and flowers. and how to use it.

0002

BACKGROUND OF THE INVENTION Plants generally continue to carry out respiration, transpiration, and other various substance metabolism even after being harvested as living organisms, and actively carry out their physiological functions to extend their lives. When this respiratory action is active, other physiological actions also become active, resulting in a decrease in freshness.

One of these metabolites is ethylene, which is a type of plant hormone. Ethylene has various physiological effects, including those that promote respiration and maturation, and are greatly involved in the maturation of plants and, ultimately, the decline in freshness. This decrease in freshness is a major problem in the storage and distribution of fruits, vegetables, and flowers, and various freshness-preserving agents with ethylene removal ability have been developed as a way to eliminate the harmful effects of ethylene's physiological effects and prevent the decrease in freshness. . They can be roughly divided into the following four types.

(1) Bromine-adsorbing activated carbon as typified by JP-A-54-70457 (2) Potassium permanganate supported as typified by JP-A-58-20149 (3) JP-A-58-20149 Potassium bromate/acid-treated activated carbon (4) typified by JP-A No. 98141 Palladium chloride-supported activated carbon typified by JP-A-61-25340

[0005]

[Problem to be solved by the invention] However, (1)
In this method, bromine is adsorbed and retained within the pores of activated carbon, so there is a risk that harmful bromine gas will be generated when the temperature rises. Method (2) uses potassium permanganate at LD501090mg/kg (rat, oral).
Since it is an environmentally designated substance, its use is practically difficult in terms of collection and treatment and pollution prevention. Method (3) involves activating an alkali bromate salt by acid treatment and retaining it on activated carbon, converting ethylene into a bromine compound, but ethylene bromide produced from ethylene is carcinogenic. It is a danger. Method (4) uses palladium chloride supported on activated carbon, which has excellent oxidative decomposition of ethylene, but the oxidation reaction is insufficient and 100% complete oxidation is not possible, so a certain amount of acetaldehyde is always used. will be generated. This acetaldehyde is also a substance that reduces the freshness of fruits and vegetables, so its production is undesirable.

As a means to overcome these drawbacks, Japanese Patent Application Laid-open No. 1-168233 describes a freshness-preserving agent in which palladium chloride, copper chloride, and zinc chloride are supported on activated carbon. There is a record that there has been no occurrence.

However, since this freshness preserving agent is made by impregnating activated carbon with an aqueous solution of palladium chloride, copper chloride, and zinc chloride and drying it, palladium chloride, copper chloride, and zinc chloride remain attached to the activated carbon. . this house,
Palladium chloride is LD50104mg/kg (mouse,
(peritoneal cavity), copper chloride is a deleterious substance with an LD50 of 140 mg/kg (rat, oral), and zinc chloride has an LD50 of 350 mg/kg (rat, oral).
mg/kg (mouse, oral), so it is dangerous to ingest activated carbon by mistake.Also, since it is attached with an aqueous solution, palladium chloride may evaporate when packaged with fruits and vegetables. , copper chloride, and zinc chloride may be eluted and attached to fruits and vegetables, and as a result, it is assumed that the person using the substance may eat the substance without realizing it.

[0008] Such drawbacks can be said to be fatal when coexisting with foods such as fruits and vegetables.

[0009] Therefore, the present inventor decomposed physiologically active substances such as ethylene and acetaldehyde generated from fruits, vegetables, and flowers into substances that are harmless to fruits, vegetables, and flowers, and which is safe even when coexisting with foods such as fruits and vegetables. As a result of intensive research into freshness preserving agents and methods of using them, we were finally able to arrive at the present invention.

0010

[Means for Solving the Problems] The present invention provides a solution containing a palladium complex salt and at least one kind selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum. The present invention relates to a freshness-preserving agent characterized in that it is formed by heat-treating a precipitate obtained by mixing a solution containing a metal salt and/or a complex salt, and a method for using the same.

The present invention will be explained in detail below.

[0012] The complex salt in the present invention refers to an electrolyte complex, that is, one that dissociates into complex ions in a solution.
A palladium complex salt is one that dissociates into palladium complex ions in a solution. The palladium complex ion in this case refers to a complex consisting of an electron pair donor and an acceptor, in which the palladium atom is the acceptor and is electrically charged. Such palladium complex salts include tetraamine palladium (divalent) salt, bis(ethylenediamine) palladium (divalent) salt, and dichloroethylenediamine palladium (divalent) salt.
Examples include divalent) salts.

[0013] In the present invention, salt is a general term for compounds in which one or more dissociable hydrogen ions contained in an acid are replaced with cations such as metal ions or ammonium ions. Magnesium, titanium, vanadium, iron, nickel, copper,
A salt consisting of at least one metal selected from zinc, molybdenum, silver, and platinum is a cation of at least one metal selected from these elements, and is a salt containing at least one metal cation selected from these elements. It refers to a compound in which a dissociable hydrogen ion is substituted, and preferred salts thereof include chlorides, sulfate compounds, and complexes. In addition, vanadium oxysulfate is preferable as a vanadium salt, and silver nitrate is preferable as a silver salt, and copper chloride and zinc chloride are more preferable.

Palladium complex salt in the present invention and magnesium, titanium, vanadium, iron, nickel, copper,
The dissolved amount of each salt and/or complex salt made of at least one metal selected from zinc, molybdenum, silver, and platinum is not particularly limited as long as it is below the saturation amount, but preferably The saturation amount is preferably 50 wt% or less. In addition, as the solvent at this time, a complex salt of palladium and a salt and/or complex salt consisting of at least one metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum are used. There is no particular limitation as long as it dissolves, but a solvent in which palladium complex salt is dissolved and at least one metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum. It is preferable that the solvent is the same as the one in which the salt and/or complex salt consisting of is dissolved, and a particularly preferable solvent is water.

[0015] The method for producing a precipitate in the present invention includes a solution in which a complex salt of palladium is dissolved and at least one kind selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum. A method of mixing with a solution in which a metal salt and/or complex salt is dissolved can be mentioned. In addition, as another method, a solution containing a complex salt of palladium is mixed with a salt consisting of at least one metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum. Alternatively, a method of producing a precipitate by mixing complex salts can be mentioned. In this case, complex salts of palladium, magnesium, titanium, vanadium, iron,
There is no particular limitation on the order of dissolving the salt and/or complex salt made of at least one metal selected from nickel, copper, zinc, molybdenum, silver, and platinum, and any method that ultimately yields a precipitate may be used. Good.

[0016] The above precipitate must then be thoroughly washed and dried. At this time, if the washing is insufficient, the precipitate after drying may include complex salts of palladium, magnesium, titanium, etc.
Salts and/or complex salts made of at least one metal selected from vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum remain attached, which is unfavorable from a safety standpoint. Therefore, the presence of impurities such as palladium complex salts and salts and/or complex salts consisting of at least one metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum in the cleaning waste liquid. The drying process should be started only after this is no longer confirmed.

[0017] The drying temperature and time in the drying step are as follows:
There are no particular limitations as long as the conditions allow the solvent to evaporate.

[0018] The heat treatment in the present invention is a process for causing the precipitate that has passed through the drying process to exhibit the ability to remove ethylene and acetaldehyde as a freshness-preserving agent, and under any conditions to develop this performance as a freshness-preserving agent. Although there is no particular limitation, it is usually preferable to heat at 200 to 800°C for 30 minutes or more. In addition, in order to carry out the drying step and the heat treatment step at the same time, there is no problem in treating the precipitate under the above heat treatment conditions immediately after washing.

[0019] In the method of using the freshness-preserving agent of the present invention in which it is dispersed and contained in a molded body, the molded body is a known type that has been conventionally used in the storage and distribution of fruits, vegetables, and flowers. as films, sheets, containers,
Examples include paper, fibers (cloth, nonwoven fabric, etc.), foam, cardboard boxes, etc.

[0020] In the present invention, when the molded product is a film, sheet, container, fiber (cloth, nonwoven fabric, etc.), or foam, the molded product is generally made from a resin as the material. In this case, the resin includes any of natural resins, semi-synthetic resins, and synthetic resins, and may be either a thermoplastic resin or a thermosetting resin. For example, polyethylene, polypropylene, vinyl chloride, ABS resin, nylon, polyester, polyvinylidene chloride, polyamide, polystyrene,
Polyacetal, polyvinyl alcohol, polycarbonate, acrylic resin, fluororesin, polyurethane elastomer, polyester elastomer, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, urethane resin, rayon, cupra,
Mention may be made of thermoplastic or thermosetting resins such as acetate, triacetate, vinylidene, natural rubber and synthetic rubber. Further, the resin may be a foamable resin.

[0021] There are no particular limitations on the timing and method of dispersing the freshness-preserving agent in the present invention into the resin as the material for the molded body. For example, a method of adding and mixing to the raw material monomer and then polymerizing, a method of adding and mixing to the reaction intermediate and then polymerizing, a method of adding and mixing to the resin after polymerization, a method of adding and mixing to the resin after polymerization, a method of heating and melting using a Banbury type mixer, a roller type mixer, etc. It is possible to use a conventional kneading method in which the resin is added to and mixed with a thermoplastic resin in a heated state. In short, an optimal method may be adopted as appropriate depending on the properties of the resin used, process characteristics, etc.

[0022] When the molded article in the present invention is a film, sheet, container, fiber, or foam, the freshness-preserving agent is often preferably in the form of powder particles. When the molded object is a thick sheet, container, thick denier fiber, granule, etc., the particle size of the freshness-preserving agent may range from several μm to several tens of μm or several hundred μm or more; In this case, the particle size of the freshness-preserving agent is preferably 5 μm or less, more preferably 3 μm or less.

When the molded product of the present invention is a film, sheet, container, fiber, or foam, the amount of the freshness-preserving agent added is preferably 0.01 to 30% by weight based on the total weight of the molded product. If the amount of the freshness-preserving agent added is below the lower limit, the freshness-preserving effect may be unsatisfactory, which is undesirable.If the amount exceeds the upper limit, for example, 50% by weight or more, the freshness-preserving effect is sufficient, but , is undesirable because the physical properties of the molded product are significantly deteriorated. A more preferable range is 0.5 to 10% by weight.

[0024] As a method for manufacturing the molded article containing the freshness-preserving agent dispersed therein in the present invention, a conventional method can be adopted. For example, when the molded product is a film or sheet, it can be obtained by adding and mixing a freshness-preserving agent to a resin by the method described above and molding (forming into a film or sheet). The film can be formed by a casting method, an extrusion method (for example, an inflation method, a T-die method, a calendar method, a cutting method, etc.), or a stretching method. The thickness of this film/sheet is not particularly limited, but is usually preferably 0.01 μm to 10 mm. At this time, when the thickness is small, it is preferable to provide the film on a support layer, and examples of the support layer include not only the above-mentioned resins but also paper and metals (eg, aluminum). When reducing the thickness of the film and providing a resin as a support layer, in other words, an ultra-thin resin layer containing a freshness-preserving agent dispersed therein (hereinafter sometimes simply referred to as layer A) and a resin constituting the support layer. When making a composite film formed by laminating layers (hereinafter simply referred to as layer B),
There is an advantage that the amount of freshness-preserving agent added to the film can be reduced. To explain more specifically, in order to more effectively exhibit the freshness-preserving effect, it is desirable to have the freshness-preserving agent as close to the surface layer of the film as possible, and the freshness-preserving agent contained by laminating the A layer thinly is desirable. The position of the agent is regulated in the thickness direction of the film, and it is unevenly distributed at a high density only on the surface layer of the film, and the ultra-thin resin layer (layer A) containing this freshness-preserving agent dispersedly protects fruits, vegetables, and flowers. By using the freshness-preserving agent in contact with the film, the amount of freshness-preserving agent added to the film can be minimized. In this case, the ultrathin resin layer (layer A) containing a freshness-preserving agent dispersed therein and the resin layer (layer B) constituting the support layer are:
There is no problem whether the resins constituting each are of the same type or different types. Further, the above-mentioned support layer may be not only a single layer but also a composite layer made of two or more types of resins, and a metal or the like may be deposited on the support layer.

[0025] When the ultra-thin resin layer (A layer) containing the above-mentioned freshness preserving agent dispersed therein and the resin layer (B layer) constituting the support layer are different types of resin, the A layer and the B layer It is also possible to provide an adhesive layer between the two.

[0026] As a method for producing a composite film of an extremely thin resin layer (layer A) containing this freshness-preserving agent dispersed therein and a resin layer (layer B) constituting the support layer, hot-fusion pressure bonding simultaneous lamination is used. method, coextrusion composite method, lamination method, extrusion lamination method, hot melt lamination method,
Dry lamination method, wet lamination method, etc. can be used. Further, in order to impart strength and other functions to the film, treatments such as sequential biaxial stretching and simultaneous biaxial stretching can also be performed.

[0027] This film/sheet may contain dispersants, polymerization catalysts, stabilizers, matting agents, brighteners, organic or inorganic pigments, inorganic fillers, various plasticizers, surfactants, There is no problem in containing other components other than the freshness preserving agent such as an antifogging agent.

[0028] When the molded article of the present invention is a container,
A resin prepared by adding and mixing a freshness-preserving agent by the method described above can be molded into a desired shape by using methods such as compression molding, injection molding, vacuum molding, and extrusion molding. In this case as well, in order to minimize the amount of freshness-preserving agent added to the container, a method is used to form a multilayer composite container in which the freshness-preserving agent is present only on the surface that will come into contact with fruits, vegetables, and flowers. can also be taken. In addition, this container may contain dispersants, polymerization catalysts, stabilizers, matting agents, brighteners, organic or inorganic pigments, inorganic fillers, and various plasticizers, surfactants, antifogging agents, etc., as necessary. It goes without saying that there is no problem in containing other ingredients than the freshness preserving agent.

[0029] When the molded article in the present invention is a fiber,
Desired fibers can be obtained by adding and mixing a freshness-preserving agent to the resin using the method described above and using a spinning method such as melt spinning, wet spinning, dry spinning, or wet/dry spinning. In this case as well, in order to minimize the amount of the freshness-preserving agent added to the fiber, the freshness-preserving agent is added and mixed only to the sheath portion of the composite fiber, such as a core-sheath structure or a multi-core sheath structure. can also be taken. By forming these fibers into a cloth shape using a known method, a desired molded article can be obtained. In addition, in the spinning step, it is also possible to form a nonwoven fabric using a known method such as a spunbond method, a melt blow method, or a flash method. In addition, this fiber may contain dispersants, polymerization catalysts, stabilizers, matting agents, brighteners, organic or inorganic pigments, inorganic fillers, various plasticizers, surfactants, antifogging agents, etc. as necessary. It goes without saying that there is no problem in containing other ingredients than the freshness preserving agent.

[0030] When the molded article in the present invention is paper, a known method can be adopted as its manufacturing method.
One method is to add and mix the freshness-preserving agent of the present invention to a pulp raw material and then form the pulp into paper. In addition, there are methods in which fibers containing the above-mentioned freshness-preserving agent dispersed therein are added and mixed as short fibers to pulp raw materials to make paper, and when applying a coating to the manufactured paper, the freshness-preserving agent is dispersed and contained in the coating agent in advance. You can adopt methods such as keeping it in place.

When the molded article of the present invention is a corrugated box, the method for manufacturing it is to add and mix it to the raw materials during the manufacturing stage of corrugated paper, or to coat the inner wall of the corrugated box with a film containing the above-mentioned freshness-preserving agent dispersed therein. A method using a film containing the above-mentioned freshness-preserving agent dispersed in the liner portion of corrugated paper, etc. can be adopted.

[0032] The form in which the freshness-preserving agent of the present invention is used to maintain the freshness of fruits, vegetables, and flowers is not particularly limited as long as it is effective, but it is usually used in aeration of paper, cloth, nonwoven fabric, etc. Generally, a predetermined amount is stored in a container made of a flexible material to form a pack.

[0033] The amount of the freshness-preserving agent of the present invention when used to maintain the freshness of fruits, vegetables, and flowers varies depending on the type and amount of fruits, vegetables, and flowers, and is not unambiguously defined; however, it is usually , 0.05 per kg of fruits, vegetables, and flowers
-20g, preferably 0.1-5g.

[0034] As a method for using the freshness-preserving agent of the present invention to maintain the freshness of fruits, vegetables, and flowers, there is a method in which the freshness-preserving agent in the form of the aforementioned pack is present in a sealed container together with the fruits, vegetables, and flowers. Common.

[0035] The airtight container referred to herein may be any of the known materials conventionally used for packaging fruits, vegetables, and flowers. Examples include paper containers such as cardboard boxes, and plastic films and sheets such as polyethylene and polypropylene. Further, examples of the sealing method include a method in which the packaging material is made into a bag and the opening is sealed with a rubber band or string, a heat seal method, a handkerchief method, and the like.

When the freshness-preserving agent of the present invention is used to maintain the freshness of fruits, vegetables, and flowers, it can be applied to all fruits, vegetables, and flowers whose freshness is accelerated by ethylene and acetaldehyde. Examples of fruits and vegetables include apples, pears, bananas, grapes, cherries, bamboo shoots, shiitake mushrooms, cabbage, green plums, sudachi, broccoli, and melons, and examples of flowers include carnations, roses, sweet peas, perennial gypsophila, and chrysanthemums. etc.

[0037] When the freshness-preserving agent of the present invention is dispersed in a molded product and used as a freshness-preserving molded product for fruits, vegetables, and flowers, it is possible to use known materials conventionally used for packaging fruits, vegetables, and flowers. Can be used similarly.

[0038] Next, the method for producing the freshness preserving agent of the present invention, its basic performance, test results on fruits and vegetables, etc. will be explained in more detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist thereof. It's not something you can do.

[0039]

[Example] ■ Production of freshness preserving agent 0.2M tetramine dichloropalladium aqueous solution 10
00ml, 0.2M copper chloride aqueous solution 1000ml, 0
．． Prepare 1000 ml of 2M zinc chloride aqueous solution, mix three types of aqueous solutions at the same time, and precipitate. Next, this precipitate was filtered and washed with water until no excess chlorine ion, palladium ion, copper ion, or zinc ion was detected in the filtrate.

[0040] Thereafter, the precipitate after washing with water was heated to 110°C.
The freshness-preserving agent (C) of the present invention was obtained by drying with hot air for 24 hours and then heat-treating at 300°C for 3 hours.

As comparative samples, tetramine dichloropalladium = 0.2 mol, copper chloride = 0.2 mol
, zinc chloride = 0.2 mol was kneaded in a mortar and heated to 110°C.
A product (D) was obtained by drying with hot air for 24 hours and then heat-treating at 300°C for 3 hours.

■ Confirmation of ethylene and acetaldehyde removal performance (Part 1) A bag-shaped bag of 30 mm x 50 mm was made of breathable non-woven fabric, and 1 g of the freshness preserving agent (C) obtained in the above section (■) was placed in the bag (C1). ) and 1 g of (D) obtained in section ■ above (D
1) and one in which nothing was added to the nonwoven fabric (E1) were prepared.

[0043] Three desiccators (with injection valves) with an internal volume of about 4500 ml are prepared, and C1 and D are placed in each desiccator.
1 and E1, inject 3.0 ml of ethylene into each desiccator, and measure the ethylene concentration and acetaldehyde concentration in each desiccator at the initial stage (after 0 hours) and after 2 hours using an ethylene gas detection tube manufactured by Gastech Co., Ltd. (No.
172, No. 172L) and an acetaldehyde gas detection tube (No. 92). The results are shown in Table 1. Example 1 uses C1, Comparative Example 1 uses D1, and Comparative Example 2 uses E1. The detection limit of the ethylene gas detection tube (No. 172L) is 0.05 ppm, and the detection limit of the acetaldehyde gas detection tube (No. 92) is 2 ppm.

[0044]

[Table 1]

■ Confirmation of ethylene and acetaldehyde removal performance (part 2) The freshness preserving agent (C) obtained in the above section (■) was made into particles with an average particle size of 1.0 μm using a commercially available crusher, By adding 0.5% by weight to the powder and mixing with a Henschel mixer, the freshness-preserving agent and the polypropylene powder were uniformly dispersed. This mixture was melt-extruded using a twin-screw extruder to create pellets (F). Next, polypropylene pellets (G) to which no freshness preserving agent (C) has been added are prepared, each pellet is fed to a separate extruder and melted, and the melts are combined in a flow tube and guided to a T-die. , molded into a composite sheet. By subjecting this composite sheet to sequential biaxial stretching, a polypropylene composite film (C2) containing the freshness-preserving agent (C) dispersed therein was obtained. The thickness of the obtained composite film was 20 μm, and the pellets (
The layer consisting of F) had a thickness of 0.5 μm, and the dispersed freshness-preserving agent (C) was unevenly distributed at a high density on the surface layer of the film. As comparison samples, a polypropylene composite film (D2) was made in the same manner except that the freshness preservation agent (C) was changed to (D) in item (E2
) was prepared.

[0046] Three desiccators (with injection valves) with an internal volume of approximately 4500 ml are prepared, and C2 and D are placed in each desiccator.
2 and E2 were cut out to have a surface area of 3200 cm2, and 3.0 ml of ethylene was injected into each desiccator to determine the ethylene concentration and acetaldehyde concentration in each desiccator at the initial stage (after 0 hours) and after 2 hours. using an ethylene gas detection tube (No.
．． 172, No. 172L) and an acetaldehyde gas detection tube (No. 92). Example 2 uses C2, Comparative Example 3 uses D2, and E2
Comparative Example 4 is the one using the above, and the results are shown in Table 2.

[0047]

[Table 2]

■ Confirmation of ethylene and acetaldehyde removal performance (Part 3) Pellets made of low density polyethylene and medium density polyethylene were placed in an intermixer containing a pair of rotating rolls, and were softened by external heating. Next, 2% by weight of the freshness-preserving agent (C) obtained in the above section (2) was added to the heated polyethylene and kneading was continued. The obtained kneaded material was taken out from the intermixer, solidified by cooling, and ground into granules. This granular material is supplied to an extruder and heated in three stages, and liquefied gas is pressurized into the heating zone of the second stage to produce a sheet-like foam (C3) with a thickness of 2 mm.
It was pushed out as As comparison samples, a sheet-like foam (D3) was prepared in the same manner except that the freshness preservation agent (C) in the above item (■) was changed to (D) in the above item (■), and a thickness in which nothing was newly dispersed was used. 2mm sheet-like foam (E3
) was prepared.

Prepare three desiccators (with injection valves) each having an internal volume of approximately 4500 ml, and place C3 and D in each desiccator.
3 and E3 were cut out to have a surface area of 1600 cm2, and 3.0 ml of ethylene was injected into each desiccator to determine the ethylene concentration and acetaldehyde concentration in each desiccator at the initial stage (after 0 hours) and after 2 hours. using an ethylene gas detection tube (No.
．． 172, No. 172L) and an acetaldehyde gas detection tube (No. 92). Example 3 uses C3, Comparative Example 5 uses D3, and E3
Comparative Example 6 uses the same method, and the results are shown in Table 3.

[0050]

[Table 3]

■Test using fruits and vegetables (Part 1) A bag of 50 mm x 50 mm was made of breathable non-woven fabric, and 5 g of the freshness preserving agent (C) in the above item (■) was placed in the bag (C4).
), and as a comparative sample, a sample (D4) containing 5 g of (D) in item (■) above was prepared.

[0052] Weigh out 400 g of broccoli, place it in a 30 μm thick polyethylene bag, and place it in the above C.
4 (Example 4), D4 (Comparative Example 7), and nothing except broccoli (Comparative Example 8)
was prepared and the opening was sealed by heat sealing. Put them in a cardboard box and block out the light.
It was left in an atmosphere at 5°C for 6 days. On the 7th day, the ethylene concentration and acetaldehyde concentration in each polyethylene bag were measured using the aforementioned ethylene gas detection tubes (No. 172 and N
o. 172L) and acetaldehyde gas detection tube (N
o. 92) to evaluate the state of green color retention. The results are shown in Table 4.

[0053]

[Table 4]

■Test using fruits and vegetables (Part 2) The polypropylene composite film with a thickness of 20 μm obtained in the above section (■)
C2) was processed into a bag shape (C5) so that the side containing the freshness preserving agent (C) dispersed therein was on the inside. Next, the sheet-like foam with a thickness of 2 mm (
C3) processed into a hemispherical fruit cap (C
6) was prepared. In addition, as each comparative sample, the polypropylene composite film (D2) obtained in the above section (■) was
One processed into a bag shape so that the side containing (D) dispersed therein is on the inside (D5), and the other processed into a bag shape from a 20 μm thick polypropylene film (E2) that does not contain a freshness preservation agent dispersed therein. (E5), a sheet-like foam (D3) obtained in the above section (■) processed into hemispherical fruit caps (D6), and a 2-mm-thick sheet-like foam without any freshness-preserving agent added and mixed ( E3) was processed into a hemispherical fruit cap (E6).

[0055] Four green plums each weighing about 30 g were placed in C5 (Example 5), four were placed in D5 (Comparative Example 9), and four green plums were placed in E5 (Comparative Example 10). ,Also,
20 μm of 4 green plums covered with the above fruit cap C6
(Example 6), 20 pieces of 4 green plums covered with fruit cap D6 were placed in a polypropylene film bag with a thickness of
Placed in a micrometer-thick polypropylene film bag (
Comparative Example 11) and 4 green plums covered with Fruit Cap E6 were placed in a 20 μm thick polypropylene film bag (Comparative Example 12), and the opening was sealed by heat sealing. Put them in a cardboard box,
It was left in an atmosphere at 10° C. for 7 days while shielding from light. On the 8th day, the ethylene concentration and acetaldehyde concentration in each polypropylene bag were measured using the aforementioned ethylene gas detection tubes (No. 172 and No. 172L) and acetaldehyde gas detection tube (No. 92), and the green color was maintained. Assessed the condition. The results are shown in Table 5.

[0056]

[Table 5]

[0057]

[Effects of the Invention] According to the present invention, physiologically active substances such as ethylene and acetaldehyde generated from fruits, vegetables, and flowers can be decomposed and removed into substances that are harmless to the fruits, vegetables, and flowers, and can coexist with foods such as fruits and vegetables. It is possible to obtain a freshness-preserving agent that is safe even when the freshness-preserving agent is present in an airtight container together with fruits, vegetables, and flowers, or by placing a molded body containing this freshness-preserving agent dispersedly into fruits, vegetables, and flowers. By using it as a packaging material or storage container, it is possible to maintain the freshness of fruits, vegetables, and flowers.

Claims (2)

[Claims] [Claim 1] A solution in which a palladium complex salt is dissolved;
A precipitate obtained by mixing a solution containing a salt and/or a complex salt consisting of at least one metal selected from magnesium, titanium, vanadium, iron, nickel, copper, zinc, molybdenum, silver, and platinum. A freshness-preserving agent characterized by being made by subjecting it to heat treatment. 2. A method of using a freshness-preserving agent, which comprises dispersing and containing the freshness-preserving agent according to claim 1 in a molded article.